Naturally, I doubt it would be called a camera-mod, as it wouldn't be accurate as Sims 1 uses polygon based images, 4 for each view, and the neighbourhood itself only has one view.
To be able to incorporate neighbourhood view's ability to see all the lots while you're playing a single lot would mean it would potentially have to load in a lot more detail every single house and family, it would slow the game down tremendously and the polygon images, again, would suffer, as there is one image for every stage of the zooming process, to be able to see it in a neighbourhood view would require additional images for further zooming out points for the further the camera gets. Unless of course you don't mind being quite zoomed in when you navigate around your neihbourhood.
Put bluntly, the game wasn't designed for such a thing, and this therefore wouldn't be doable.
Hope I helped